Table 3.
Efficacy against Persistent Infection with HPV Type 6, 11, 16, or 18 and against Detection of HPV DNA in the Intention-to-Treat Population.*
| Variable | Quadrivalent HPV Vaccine (N = 1817) | Placebo (N = 1815) | Observed Efficacy % (95% CI) |
||||||
|---|---|---|---|---|---|---|---|---|---|
| No. of Subjects | Cases no. |
Person-Yr at Risk | Rate no./100 person-yr at risk |
No. of Subjects | Cases no. |
Person-Yr at Risk | Rate no./100 person-yr at risk |
||
| Persistent infection† | |||||||||
| HPV type | |||||||||
| Type 6, 11, 16, or 18 | 1817 | 148 | 4094.3 | 3.61 | 1815 | 273 | 3942.6 | 6.92 | 47.8 (36.0 to 57.6) |
| Type 6 | 1817 | 63 | 4213.8 | 1.50 | 1815 | 112 | 4139.4 | 2.71 | 44.7 (24.1 to 60.1) |
| Type 11 | 1817 | 16 | 4284.6 | 0.37 | 1815 | 39 | 4238.7 | 0.92 | 59.4 (25.7 to 78.8) |
| Type 16 | 1817 | 71 | 4199.5 | 1.69 | 1815 | 131 | 4112.7 | 3.19 | 46.9 (28.6 to 60.8) |
| Type 18 | 1817 | 25 | 4267.0 | 0.59 | 1815 | 56 | 4210.1 | 1.33 | 56.0 (28.2 to 73.7) |
| Sexual orientation | |||||||||
| Heterosexual males | 1542 | 96 | 3723.7 | 2.58 | 1541 | 187 | 3596.8 | 5.20 | 50.4 (36.2 to 61.6) |
| Males who had sex with male partners | 275 | 52 | 370.6 | 14.03 | 274 | 86 | 345.8 | 24.87 | 43.6 (19.5 to 60.8) |
| DNA detection | |||||||||
| HPV type | |||||||||
| Type 6, 11, 16, or 18 | 1817 | 384 | 3851.1 | 9.97 | 1815 | 511 | 3736.5 | 13.68 | 27.1 (16.6 to 36.3) |
| Type 6 | 1817 | 158 | 4123.4 | 3.83 | 1815 | 239 | 4047.5 | 5.90 | 35.1 (20.3 to 47.3) |
| Type 11 | 1817 | 50 | 4254.0 | 1.18 | 1815 | 87 | 4202.6 | 2.07 | 43.2 (18.7 to 60.7) |
| Type 16 | 1817 | 189 | 4070.9 | 4.64 | 1815 | 259 | 4014.2 | 6.45 | 28.0 (12.9 to 40.7) |
| Type 18 | 1817 | 89 | 4205.4 | 2.12 | 1815 | 133 | 4151.5 | 3.20 | 33.9 (13.0 to 50.1) |
| Sexual orientation | |||||||||
| Heterosexual males | 1542 | 268 | 3516.2 | 7.62 | 1541 | 379 | 3416.8 | 11.09 | 31.3 (19.4 to 41.5) |
| Males who had sex with male partners | 275 | 116 | 334.9 | 34.64 | 274 | 132 | 319.7 | 41.29 | 16.1 (−8.5 to 35.2) |
*
Data are shown for subjects who had at least one follow-up visit after day 1. HPV denotes human papillomavirus.
†
Persistent infection was defined as detection of the same HPV type (6, 11, 16, or 18) in anogenital swab or biopsy specimens collected on two or more consecutive visits, with an interval of at least 6 months (±1 month) between the visits. Subjects in whom DNA for HPV type 6, 11, 16, or 18 was detected at one or more visits were counted as cases for the DNA detection end point.